Lincoln Locker?

[Roy]

Anybody have any general suggestions for welding up an open differential? All I can find on the web is "weld the spider gears together". Duh.

Should I machine some inserts to keep the side gears centered while welding? Or maybe just shove some old shafts in there?

No need to try and talk me out of this. I've got 4 gearboxes, one that already has a crappy LSD in it, so I've made up my mind to try el spoolo.

[Sue Salsburg]

The guy who welded ours made little pieces to block the gears from moving & then welded to them. If you just weld the spiders, the shock will probably crack the welds over time. Ask me what happens then - a long story that involves 3 barrel rolls & 2 endos. Sue

[Tim Royer]

HI,

I won't recommend any welded, fixed, or spool differential in the kind of racing we do. The only racing format that it's good for is drag racing in a straight line. Think about it. If you have welded the spiders on a front wheel drive car you would have the worst push into the turn.

Say you take a right turn in that front wheel drive car. Your right tires needs to take fewer revolutions then the left to take that turn. If they are fixed or welded they will not be able to do that, they are forced to both do the same revolutions causing the tires to scrub through the turn the whole way. This will cause the car going into the turn to push left so bad you will have to take it much slower.

The best thing to get for front wheel or rear wheel drive is a locker type or even a completion style limited slip. Open rears stink I agree, I know my limited slip stinks because I find myself doing one wheel peels if the rear is loaded heavy to one side.

It will of course give you better traction say at the wall at Weatherly and everywhere else you found yourself having low traction. But you will be slower everywhere else.

So bottom line is I guess if you drive like Grandma through the turns then unleash a ton of ponies to the next turn you’ll be happy with it. If you’re driving the turns hard you will hate it. Hey, try it I guess.

[svann]

I have some experience with a locked (welded) rear in a rear drive Camaro SS. In high speed autocrosses that we use to run at airports in the 80s, it would cause understeer on turn in but was good on exit with full power. It seemed to work the best on high speed sweepers. I'd think on front drivers it would be a problem however.

[Roy]

Tim,

While I agree with what you are saying, several people who run swifts in IT and Production have proven that while the car becomes much more "interesting" to drive, it also becomes much faster. A fellow who runs a G production swift told me that he knocked 3 seconds off his lap times at mid-ohio (on the same weekend) after having the his diff welded at the track.

Like I said, my mind is made up. The locked diff is definately going in the car. I can always swap out the gearbox if I don't like it, but I think it's for the better.

--Roy

[Steve Tumolo]

Just something to add. I know that welding the diff's is common practice in front wheel drive race cars. But one very important thing to remember is that in road racing the corners are not near as sarp as the turns in most of our hillclimbs. Not to mention the speeds that you carry through a turn on a road coarse help to overcome the tire scrub Tim mentioned.


Good Luck

[Roy]

*sigh*

Yes, I realize this. Roadcouses DO have hairpins. This car (being ITB) is and will continue to be raced on roadcoarses). I already have a "point and shoot" driving style... blah, blah, blah.

I know all the pro's and con's of a locked diff. Don't need to rehash them as we've all heard them a million times.

The diff is getting welded. If I don't like it, i'll put the POS OPM back in.

[Steve Tumolo]

We are just the voices of reason trying to help ya Heck, if it were my car I would convert it to rear wheel drive and put a small block Ford in it. Then it would really be point and shoot,,,LOL.

[Bigfork]

We are just the voices of reason trying to help ya

There's a reason all of Roy's friends refer to him as the cantankerous old bastard

It'll be an interesting experiment and I'm sure it'll be a learning experience for both of us when it comes time to drive it. The Swift's greatest attribute is it's corner speed. If that is severely compromised we'll know pretty quick I think.

Tony

[Matt Rowe]

I'll be interested to see how this works as well. I seen similar claims by road racers running FWDs with welded diffs and all I can say is I can't imagine it helping my car. Especially not on a hill where the corner radii at places like Weatherly and Duryea or easily twice as bad as any road course I've even heard of.

Still, it doesn't hurt to experiment, especially if you have a free trans, welder and some free time. The only thing better is having someone else do all the work and try it on their car.

[Bigfork]

The only thing better is having someone else do all the work and try it on their car.

*cough* *cough* Um, yeah... good idea... *cough*

Tony - Not so sure how long I'll have co-driver privileges

[Richard Elliott]

In the Steve Smith book "How to build a mini-stock" he show what he says is the best way to weld one up. He says to NEVER arc weld one, as it will fail do to the excesive heat from arc welding. He says to braze the area between two teeth completely up level with the top of the two teeth. Then go 180 deg around the gear and do it again. Says to use NEW gears too.